Fifteen haplochromine species from Lake Kivu, a deep natural dam lake on the Rwandese-Zairean border, have been described or redescribed. All species are endemic to the lake. Taxonomic novelties include the description of three new species.
For each species, the relevant literature is discussed and a detailed morphological description is given. Data of both sexes have been reviewed separately to check for sexual dimorphism. A detailed colour description of live specimens as well as preserved specimens is given separately for males
and females. For the description of live colour pattern, a colour scale has been used.
Four species are polychromatic. Haplochromis vitttatus, H. adolphifrederici and H. occultidens have a normal coloured and a piebald or bicolor morph. H. paucidens also has a third, rare grey morph. Samples of all morphs have been examined in order to investigate possible inter-morphic differences.
When available, ecological data have been included and discussed with respect to the morphology of the species.
Diagnoses have been provided for each species. As morphological characters largely overlap and few Lake Kivu species are discernable on a limited number of features, the diagnoses of some species are rather complicated. Due to this complexity, a simple dichotomous determination key could not be compiled. Instead, some guidelines for determination are given, starting from some easy to determine morphological features.
This study ends with an annotated bibliography that of all chapters expresses best the complexity of Lake Kivu haplochromine taxonomy. Speciﬁc names that refer to a group of ﬁve or more different species are not rare at all in the existing literature.